Battles & Wars › Greece, Rome & Han › Roman Empire
Battle of Actium
September 2, 31 BC· Battle· Europe
Well documentedSolid records, physical evidence or scientific consensus.
Octavian's fleet, led by Agrippa, defeated Mark Antony and Cleopatra off western Greece, leaving Octavian sole master of Rome.
See it on the Battles & Wars map →What happened
After Caesar's murder, his heir Octavian and his general Mark Antony split the Roman world. Antony allied with, and married, Cleopatra VII of Egypt. Their fleet and army were bottled up at Actium in western Greece, weakened by disease and desertion. On September 2, 31 BC they tried to break out. Cleopatra's squadron, then Antony, escaped to Egypt; most of the fleet was lost or surrendered, and the army gave up days later. Both died by suicide in Alexandria in 30 BC.
Why it matters
It ended a century of Roman civil wars and brought Egypt, the richest land in the Mediterranean, under Rome. Octavian became Augustus, the first emperor.
How we know
Roman accounts by Plutarch, Cassius Dio and court poets like Virgil, all favoring Octavian. His victory monument near the site, with sockets that held captured bronze ship rams, has been excavated.
Still debated
Whether Cleopatra's flight was a planned breakout or panic, and how large the fleets were, remain debated; the victors wrote the story.
Connections (4)
▸Julius Caesar was assassinated, starting civil wars ending at Battle of ActiumWell documented
The connection
Caesar's murder in 44 BC did not restore the Republic. His heir Octavian and his lieutenant Mark Antony first beat the assassins Brutus and Cassius at Philippi in 42 BC, then divided the empire between them. Their rivalry grew into the final civil war, settled at Actium.
When and how
Rome, March 15, 44 BC; Philippi in Macedonia, 42 BC; Actium, western Greece, 31 BC.
How we know
Cicero's letters and speeches, Appian's Civil Wars and Cassius Dio document the chain of events step by step.
Debates and open questions
Whether a different settlement after the assassination could have saved the Republic is a counterfactual historians still argue.
▸Battle of Actium led to the founding of Roman EmpireWell documented
The connection
With Antony and Cleopatra dead and Egypt annexed in 30 BC, Octavian had no rival left. In 27 BC the Senate gave him the name Augustus. He kept the Republic's offices but held the real power, the army and the money. Historians conventionally date the Roman Empire from then.
When and how
Actium, September 2, 31 BC; Alexandria, August 30 BC; Rome, January 27 BC.
How we know
Augustus's own record of his deeds, the Res Gestae, inscribed in stone, plus Cassius Dio and coins celebrating the capture of Egypt.
Debates and open questions
Exactly when the Republic ended, at Actium, in 27 BC, or gradually, is partly a matter of definition.
▸Battle of Lepanto was the greatest galley battle since Battle of ActiumMostly agreed
The connection
Lepanto was fought roughly 100 kilometers south of Actium, in the same waters off western Greece. Both were huge clashes of oared warships, decided largely by close fighting. With over 400 galleys and well over 100,000 men, Lepanto is often called the largest galley battle since antiquity, and it was the last major one: gun-armed sailing ships soon took over.
When and how
Actium, Gulf of Ambracia, 31 BC (Octavian against Antony and Cleopatra); Lepanto, near the Gulf of Patras, October 7, 1571.
How sure are we?
The comparison is historians' own; fleet sizes and tactics are recorded for both battles. The link is a parallel, not a cause.
Debates and open questions
Ancient fleet sizes at Actium and Salamis are uncertain, so 'largest since' rankings are rough.
▸Trireme and the ramming warship evolved into the heavier galleys of Battle of ActiumMostly agreed
The connection
After about 400 BC, navies built bigger galleys called 'fours', 'fives' and larger, with more rowers per oar, heavier rams, and room for catapults and marines. At Actium, Mark Antony's big warships faced Octavian's lighter, more agile fleet under his admiral Agrippa, and lost.
When and how
Off Actium in western Greece, September 2, 31 BC: Antony and Cleopatra against Octavian and Agrippa.
How sure are we?
Sockets for captured bronze rams on Octavian's victory monument near Actium show how large the warships were.
Debates and open questions
Whether Antony meant to fight or only to break out and flee to Egypt is debated, as is how much ship size really mattered.